Magnesium alloys



Patented Dec. 31, 19 40 PATENT OFFICE MAGNESIUM ALLOYS Fritz Christen, Zurich-Altstetten, Switzerland No Drawing. Applicati No. 314,150. In Swi 1 Claim.

The invention relates to a pre-alloy (master batch alloy) for the production of magnesium alloys.

The magnesium alloys hitherto known for die- 5 casting do not exhibit sufilcient tensile strength and they also exhibit defects in respect of adequate ductility so that the possibility of using them is still very limited.

These defects are avoided by preparing the 10 alloy by admixture with magnesium of the prealloy according to the invention in an amount lying within the limits of 3-14% and varying in accordance with the purpose for which the resultant alloys are to be used.

If The pre-alloy according to the invention has the following composition:

Per cent (1) Aluminium 44 -30 (2) Zinc 24. 5-41 (3) Manganese 21 4 (4) Nickel 3. 5 8 (5) Magnesium 26 17 In accordance with the use of rising or falling percentages of the corresponding components 1 5 and 2, 3 and 4 and in accordance with the choice of the amount of this pre-alloy in the final alloy within the range of 13-14%, the properties of the latter vary in respect of tensile strength and/or ductility.

In comparison with the die-casting alloys hitherto known, the use of a pre-alloy according to the invention gives a magnesium alloy with a much greater tensile strength and ductility than 35 could hitherto be obtained and the new alloy is also suitable for other forms of casting.

The possibility is also aflorded of predetermining precisely what properties the final alloy is to have by altering the percentages of the elements on January 16, 1940, Serial tzerland April 27, 1939 in the pre-alloy and the percentage of the prealloy in the final alloy.

Thus for example a greater tensile strength of the final alloy is obtained if the percentage of the pre-alloy is increased. 5

The ductility can for example be increased by' choosing the higher percentages of the elements aluminium and zinc with corresponding reduction of the percentage of "the element nickel.

Example The pre-alloy consisting of the above composition and produced in a suitable manner .is added in a preheated condition at about 100 C. to the actual magnesium melt, the percentage added being within the prescribed limits, The 15 added pre-alloy slowly dissolves in the melt.

During this melting operation the customary flux rises to the surface and covers the melt. When everything has become fluid the melt is thoroughly stirred and heated further to 800- 900 C.

Then the crucible is removed from the furnace and after'waiting some minutes for it to cool down to the casting temperature of 700-750 C.,' the alloy is cast into pigs or moulded blocks.

I claim:

As an article of new manufacture for use in the production of magnesium alloys, a pre-alloy of the following composition:

Percent (1) Aluminium 44 -30 (2) Zinc 24. 5-41 (3) Manganese 2 4 (4) Nivkel 3. 5- 8 (5) Magnesium 26 -17 FRITZ CHRISTEN. 

